We have an allotment, and the new guy who has the plot next door is very keen on chemicals. He sprinkles powdered fertiliser (perhaps fish and bone meal?) over the whole plot every few weeks. As it isn't dug in, it wafts about in the breeze for a week or two after. The smell is unpleasant, but I'm most worried about whether it's safe to breathe, being pregnant. Does anyone know? Thanks.